Core catcher



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CORE CATCHER Filed Aug. 19, 1946 l km.; 9

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ATTORNEYS Patented Apr. 4, 1950 isaiasi T `OIF AFil CE CORE CATCHER ...J-clin C. 'Stokes, Houston, Tex.,. assignortoileed RollenBit Company, Houston, Tex.,- a.-y corporation. of .Texas Application August 19, 1946,"Serial Noi 691,639

(Cl.` Z55-7.2)

:are damaged .or destroyed.

Other fobjects. of .the.invention will hereinafter appear.

FThe preferred embodiment :of 'the invention is illustrated {.by .the ,accompanying drawings .in which .'Fig `1 is a sectional elevation ofthelower end of a deep well core drill with the catcher therein in its upper inactive position; Fig. 2, a View similar to Fig. 1 with the catcher in its lower active position; Fig. 3, a sectional elevation of the core catcher; Fig. 4, a horizontal section on the line Q -4 of Fig. 3; and Figs. 5, 6, and '7 are views illustrating the manufacture of the spring finger from a, metallic strip.

Referring to Fig. l, the numeral I indicates the conventional deep well drill stem and the numeral 2 a conventional bit threaded on the lower end thereof.

The bit Z is hollow to receive the core cut by the cutting teeth 3 and it has an internal downwardly tapered seat 4. Within the bit 2 and cooperating with the Seat 4 is the new and improved core catcher provided by this invention.

The core catcher is illustrated in detail by Fig. 3. It includes a ring 5 which is slidable up and down in the bit head 2 and has depending therefrom circumferentially spaced spring lingers E. The ring 5 has internal circumferentially spaced recesses 1 to receive the upper ends of the spring fingers 6 and said fingers are riveted in said recesses as indicatd at 8. The spring fingers may be made of a higher carbon steel than the ring 5 to which they are thus attached.

The lower ends of the spring fingers 6 are bent inwardly, as indicated at 6a t0 slide inwardly on the seat 4 of the bit head 2, as indicated in Figs. l and 2. The bent portions 6a. of the spring ngers have claws 5b extending inwardly from opposite sides of said bent portions to engage a hard core when the catcher is in the position shown by Fig. 2. The spring fingers 6 may, therefore, be referred to as the hard formation spring fingers,

Riveted as indicated at 9 to the hard formation spring ngers 6 and extending upwardly and 2 inwardly to 'engage ilthe core fare *soft formation spring .fingers IMJ. `lTl'iesesoft formation-spring fingers lll .fare mounted .on :every .other fone of thelhard formationispring lingers 6 'as shown, and" they function not' only to retain a soft'formation .corezin thecorefcatcherI but: alsotov cause -Yth'e core catcher vto move'downwardly upon the seat 'it and thereby bring the claws :tibiA into: engagement with the hard f crm-ation .core wheni thefdiillA stem is pulledupwardly.

Referring-to fFigs. `5,6, :and y'-7,'the hard formation .coreiingerszarermade bystampingfthef'spring Vfinger :shown :by fFig. f6 from lthe :metal st'ripft andi then.y bending fthe lwing iportion's ylib inwardly Vthrough substantially `degrees to form the Lspacedy claws fb.

It will be :apparent @to those skilled `in the ar-t that the method of making this core catcher reduces ma-chining to a minimum, and that when made the core catcher will eiliciently perform its function and that its parts may be readily replaced when damaged or destroyed.

It will be understood that the spring fingers 6 and I0 have been referred to as the hard formation and soft formation spring lingers, respectively, for convenience in description.

The invention is not limited to the preferred embodiment disclosed. Various changes will occur to those skilled in the art, within the scope of the following claims.

I claim:

1. A core drill including a hollow head having an internal downwardly tapered seat, and a core catcher in said head, said catcher including a ring slidable axially in said head and having circumferentially spaced recesses, circumferentially spaced hard formation spring iingers riveted in said recesses and extending downwardly and having inwardly bent lower portions to slide inwardly on said seat upon downward movement of said catcher, said bent portions having claws extending inwardly from opposite sides of said bent portions to engage a core, and soft formation spring lingers riveted to said hard formation fingers at positions spaced from said ring and extending upwardly and inwardly to engage a core.

2. A core drill including a hollow head having an internal downwardly tapered seat, and a core catcher in said head, said catcher including a ring slidable axially in said head and having cir cumferentially spaced recesses, and circumferentially spaced spring fingers riveted in said recesses and extending downwardly and having inwardly bent lower portions to slide inwardly on said hard formation ngers at positions spaced y from said ring and extending upwardly and inwardly to engage a core.

4. A core catcher including a ring, and circumferentially spaced spring fingers riveted to said ring and extending downwardly and having integral inwardly bent lower portions, said bent poru tions having integral laterally spaced claws extending inwardly from opposite longitudinal edges of said bent portions to engage a core.

5. A core catcher including a ring, circumferentially spaced spring ngers joined to and depending from said ring, and soft formation core catcher spring fingers secured to said rst spring ngers at positions spaced from said ring and extending back along said first fingers toward the ring and inwardly toward the axis of the ring.

6. A core catcher including a ring, circumferentially spaced spring ngers joined to and depending from said ring, and having integral inwardly bent lower portions, the bent portion of each linger having integral laterally spaced claws extending inwardly from opposite longitudinal edges of said bent portions to engage a core.

'7. A core catcher including a ring, circumferentially spaced spring ngers joined to and depending from said ring, and having integral inwardly bent lower portions, said bent portions having integral laterally spaced claws extending inwardly from opposite sides of said bent portions to engage a core, and soft formation core catcher spring lingers secured to said rst spring iingers at positions spaced from said ring and adjacent said inwardly bent portions of said rst ngers and extending back along said iirst fingers toward the ring and inwardly toward the axis of the ring.

8. A core catcher including a ring, circumferentially spaced spring fingers joined to and depending from said ring, and having integral inwardly bent lower portions, and soft formation -core catcher spring fingers secured to said rst spring iingers at positions spaced from said ring and adjacent said inwardly bent portions of said rst iingers and extending back along said first fingers toward the ring and inwardly toward the axis of the ring.

JOHN C. STOKES.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 327,943 Griscom Oct. 6, 1885 764,664 Jones July 12, 1904 1,582,904 Conrey May 4, 1926 1,588,034 Koehler June 8, 1926 2,014,806 Howard et al. Sept. 17, 1935 Hoffoss Apr. 26, 1938 

